Answer: a) 120° b) 60° c) 45°
Step-by-step explanation:
a) a. √2cos(x) + 1 = 0
We need to make 'x' the subject of the formula first
√2cos(x) = 0-1
√2cos(x) = -1
Cos(x) = -1/√2
x = arccos(-1/2)
x = -60°
Since cosine is negative in second and third quadrant, X = 180-60 = 120° (2nd quadrant)
X = 180+60 = 240°(3rd quadrant)
We will go for x= 120° being the lesser value.
b) tan(x) - √3 = 0
tan(x) = √3
x = arctan√3
x = 60°
c) sin2x-1 =0
Sin2x = 1
2x = arcsin1
2x = 90°
x = 90°/2
x = 45°
